Currently plate diffusers are installed in aeration devices installed in aeration basins of a lot of municipal waste water treatment plants.
A ceramic plate diffuser was employed conventionally. However, a plastic plate diffuser subsequently has been manufactured, which is light, has good workability, can change bubble size easily, is manufactured easily, and is cheap. It has the same size as a ceramic plate diffuser and is easy to replace a ceramic one with a plastic one. A plastic plate diffuser can easily replace a ceramic plate diffuser, using a holder for a ceramic plate diffuser as it is.
Furthermore, a membrane diffuser of an ultrafine bubble type has been used due to its high efficiency on behalf of the plate diffusers and tube diffusers made of a porous polymer.